software.amazon.awssdk.retries.api.BackoffStrategy Maven / Gradle / Ivy
/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package software.amazon.awssdk.retries.api;
import java.time.Duration;
import java.util.concurrent.ThreadLocalRandom;
import software.amazon.awssdk.annotations.SdkPublicApi;
import software.amazon.awssdk.annotations.ThreadSafe;
import software.amazon.awssdk.retries.api.internal.backoff.ExponentialDelayWithHalfJitter;
import software.amazon.awssdk.retries.api.internal.backoff.ExponentialDelayWithJitter;
import software.amazon.awssdk.retries.api.internal.backoff.ExponentialDelayWithoutJitter;
import software.amazon.awssdk.retries.api.internal.backoff.FixedDelayWithJitter;
import software.amazon.awssdk.retries.api.internal.backoff.FixedDelayWithoutJitter;
import software.amazon.awssdk.retries.api.internal.backoff.Immediately;
/**
* Determines how long to wait before each execution attempt.
*/
@SdkPublicApi
@ThreadSafe
public interface BackoffStrategy {
/**
* Compute the amount of time to wait before the provided attempt number is executed.
*
* @param attempt The attempt to compute the delay for, starting at one.
* @throws IllegalArgumentException If the given attempt is less or equal to zero.
*/
Duration computeDelay(int attempt);
/**
* Do not back off: retry immediately.
*/
static BackoffStrategy retryImmediately() {
return new Immediately();
}
/**
* Wait for a random period of time between 0ms and the provided delay.
*/
static BackoffStrategy fixedDelay(Duration delay) {
return new FixedDelayWithJitter(ThreadLocalRandom::current, delay);
}
/**
* Wait for a period of time equal to the provided delay.
*/
static BackoffStrategy fixedDelayWithoutJitter(Duration delay) {
return new FixedDelayWithoutJitter(delay);
}
/**
* Wait for a random period of time between 0ms and an exponentially increasing amount of time between each subsequent attempt
* of the same call.
*
* Specifically, the first attempt waits 0ms, and each subsequent attempt waits between
* 0ms and {@code min(maxDelay, baseDelay * (1 << (attempt - 2)))}.
*/
static BackoffStrategy exponentialDelay(Duration baseDelay, Duration maxDelay) {
return new ExponentialDelayWithJitter(ThreadLocalRandom::current, baseDelay, maxDelay);
}
/**
* Wait for a random period of time with an upper bound of exponentially increasing amount of time between each subsequent
* attempt of the same call and a lower bound of half the amount of the computed exponential delay.
*
*
Specifically, the first attempt waits 0ms, and each subsequent attempt waits between
* {@code min(maxDelay, baseDelay * (1 << (attempt - 2))) / 2} and {@code min(maxDelay, baseDelay * (1 << (attempt - 2))) +
* 1}.
*/
static BackoffStrategy exponentialDelayHalfJitter(Duration baseDelay, Duration maxDelay) {
return new ExponentialDelayWithHalfJitter(ThreadLocalRandom::current, baseDelay, maxDelay);
}
/**
* Wait for an exponentially increasing amount of time between each subsequent attempt of the same call.
*
*
Specifically, the first attempt waits 0ms, and each subsequent attempt waits for
* {@code min(maxDelay, baseDelay * (1 << (attempt - 2)))}.
*/
static BackoffStrategy exponentialDelayWithoutJitter(Duration baseDelay, Duration maxDelay) {
return new ExponentialDelayWithoutJitter(baseDelay, maxDelay);
}
}